Method for co-processing metallurgical solid waste with hazardous waste

Abstract

The application discloses a kind of metallurgical solid dangerous waste collaborative disposal utilization method, with oily sludge, desulfurization slag, converter steel slag tailings and sintering return ore as raw material, specifically comprising the following steps: first mixing, paving, repeating first mixing and paving, second mixing, sintering, crushing and screening to obtain sintered ore.The metallurgical solid dangerous waste collaborative disposal utilization method provided by the application effectively solves the problem of high moisture content of oily sludge and difficulty in dispersion by utilizing the water absorption and loose structure characteristics of desulfurization slag, and the addition of steel slag can effectively prevent self-agglomeration of desulfurization slag after being exposed to water, allowing oily sludge to be evenly distributed in sintering ingredients for sintering collaborative disposal, truly realizing the harmless and resource utilization of various metallurgical wastes, and achieving the purpose of direct reuse of metallurgical solid dangerous waste treatment without leaving the factory, energy saving and emission reduction, and cost reduction.

Description

Technical Field

[0001] This invention relates to the field of solid waste environmental protection treatment technology, specifically to a method for the co-processing and utilization of metallurgical solid and hazardous waste. Background Technology

[0002] Oily sludge from steel rolling mills is a difficult-to-dispose-of solid waste containing iron scale, lubricating oil, and water, generated during the cold rolling, hot rolling, continuous casting, and steel pipe manufacturing processes in steel plants. According to the National Hazardous Waste List, metallurgical oily sludge is classified as hazardous waste. Its treatment methods mainly include solidification, underground storage, and landfilling. These processes are lengthy, difficult to completely render harmless, and require significant land use. Due to the complex composition, high water content, and tendency to agglomerate, improper outsourcing of treatment of oily sludge from steel plants can cause serious environmental pollution.

[0003] The desulfurization slag, a byproduct of calcium-based fixed-bed desulfurization process, is calcium-based and granular. If it is used in the building materials field, it needs to be ground, and the presence of a small amount of CaSO3 will cause adverse effects such as prolonged setting time and reduced compressive strength of the building materials. Therefore, it cannot be utilized as a resource due to long-term accumulation.

[0004] In response to the current problems in the treatment of oily sludge in metallurgical solid waste, such as long treatment processes, difficulty in achieving complete harmlessness, and large land occupation, as well as the long-term accumulation of desulfurization slag that cannot be utilized as a resource, there is an urgent need to provide an environmentally friendly solution for the disposal of metallurgical solid and hazardous waste. This solution aims to achieve the goals of harmlessness and resource utilization of metallurgical solid and hazardous waste, enabling metallurgical enterprises to directly reuse solid and hazardous waste without leaving the plant, save energy, reduce emissions, and lower costs. Summary of the Invention

[0005] To overcome the shortcomings of the above technologies, this invention provides a method for the co-processing and utilization of metallurgical solid and hazardous waste, which solves the land encroachment problem caused by the inability to utilize metallurgical hazardous waste such as oily sludge, and at the same time solves the problem of long-term accumulation of desulfurization slag that cannot be utilized as a resource. It has the advantages of thorough treatment effect and no secondary pollution.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A method for the co-processing and utilization of metallurgical solid and hazardous waste, characterized by using oily sludge, desulfurization slag, converter steel slag tailings, and sintered return ore as raw materials, includes the following steps:

[0008] 1) Primary mixing: The oily sludge, desulfurization slag and converter steel slag tailings are put into a high-power mixer in a set ratio and mixed evenly to complete the first dispersion treatment of the oily sludge.

[0009] 2) Spreading: Spread the sintered return ore on the ground of the hazardous waste storage room; spread the mixture after one mixing on the top layer of sintered return ore;

[0010] 3) Repeat the mixing and spreading process once: alternately spread the sintered return ore and the mixture after the first mixing to form a thick layer, and let it stand.

[0011] 4) Secondary mixing: The material in the thick layer is mixed a second time until there are no obvious agglomerates or lumps;

[0012] 5) Sintering: A base material and a raw material layer are laid from bottom to top in the sintering machine beforehand. Then, the mixture after secondary mixing is sent to the sintering machine and laid on the raw material layer. Finally, another raw material layer is laid on the mixture after secondary mixing to form a sintering material layer. The sintering material layer is preheated, sintered and cooled in sequence.

[0013] 6) Crushing and screening to obtain sintered ore.

[0014] Preferably, the mass ratio of the raw materials is: 1-3 parts oily sludge, 10-20 parts desulfurization slag, 10-15 parts converter steel slag, and 67-79 parts sintering return ore.

[0015] Preferably, the oily sludge is a difficult-to-dispose solid waste produced by a steel plant that contains iron scale, lubricating oil, and water.

[0016] Preferably, the desulfurization residue is a desulfurization byproduct of a calcium-based fixed-bed desulfurization process.

[0017] Preferably, the converter slag tailings are slag tailings with a particle size of 0-3mm after magnetic separation and screening.

[0018] Preferably, the sintered return ore is incompletely sintered ore with a particle size ≤5mm after sieving.

[0019] Preferably, in step 2), the weight ratio of the mixture after one mixing to the sintered return ore is 21-28:67-79; the spreading thickness of the sintered return ore is 30-40cm; and the spreading thickness of the mixture after one mixing is 3-5cm.

[0020] Preferably, in step 3), the thickness of the thick material layer is 66-90cm, and the standing time is 1-2h.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0022] The metallurgical solid and hazardous waste co-processing and utilization method of the present invention not only harmlessly treats oily sludge but also effectively recovers iron and heat energy from it, with a sintering temperature of up to 1500℃, effectively avoiding the formation of dioxins during combustion.

[0023] Second, the co-processing and utilization method for metallurgical solid and hazardous waste of the present invention utilizes the hygroscopic properties and granular morphology of desulfurization slag, which effectively solves the application problem of high water content and easy agglomeration of oily sludge.

[0024] Third, the metallurgical solid and hazardous waste co-processing and utilization method of the present invention utilizes the multi-faceted and porous structure of converter steel slag tailings, which further improves the dispersibility of oily sludge while reducing the amount of CaO and MgO added during sintering; the large amount of CaSO4 in the desulfurization slag can adsorb the water trapped in the oily sludge, and the addition of steel slag can effectively prevent the desulfurization slag from self-caking after encountering water. The mixing of the three can better ensure the dispersibility and uniformity of the mixture.

[0025] Fourth, the metallurgical solid and hazardous waste co-processing and utilization method of the present invention utilizes a large amount of sintered return ore to further disperse harmful elements in oily sludge, desulfurization slag and converter steel slag tailings, thus avoiding the adverse effects of their enrichment on the sintering process.

[0026] Fifth, the multi-layer sintering method used in the metallurgical solid and hazardous waste co-processing and utilization method of the present invention, while ensuring sintering permeability, locks the trace amounts of volatile organic compounds generated during the sintering process of the solid and hazardous waste mixture in the sintered ore, avoiding damage to the sintering dust collection system and flue gas purification process system.

[0027] VI. The process of this invention is simple, the raw material is solid waste, and there is no need to add equipment on the basis of existing processes, resulting in significant technical and economic benefits.

[0028] In summary, the metallurgical solid and hazardous waste co-processing and utilization method provided by this invention effectively solves the problems of high water content and difficulty in dispersing oily sludge by utilizing the water absorption and loose structural characteristics of desulfurization slag itself. This allows it to be uniformly incorporated into the sintering batch for co-processing in sintering, truly realizing the harmless and resource-based utilization of various metallurgical wastes. It achieves the goals of direct reuse of solid and hazardous wastes without leaving the metallurgical plant, energy conservation and emission reduction, and cost reduction for metallurgical enterprises. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the multi-layer material laying and sintering of the present invention. Detailed Implementation

[0030] To better explain the present invention, the main contents of the present invention are further illustrated below with reference to specific embodiments, but the contents of the present invention are not limited to the following embodiments.

[0031] Example 1

[0032] A method for the co-processing and utilization of metallurgical solid and hazardous waste, wherein the raw materials are proportioned by weight as follows: 1 part oily sludge, 10 parts desulfurization slag, 10 parts converter steel slag tailings, and 79 parts sintering return ore, comprising the following steps:

[0033] 1) Primary mixing: The oily sludge, desulfurization slag and converter steel slag tailings are mixed evenly in a ratio of 1:10:10 in a high-power mixer to complete the first dispersion treatment of the oily sludge.

[0034] 2) Spreading: Spread the mixed material after one mixing with the sintered return ore at a weight ratio of 21:79 on the ground of the hazardous waste storage room, with the sintered return ore being 30-40cm thick; spread the mixed material after one mixing on top of the sintered return ore, with the mixed material being 3-5cm thick.

[0035] 3) Repeat the above two steps once, and then lay another layer of sintered return ore and another layer of the mixture after the first mixing on the top of the mixture, so as to form a thick layer of 66-90cm. Let it stand for 2 hours.

[0036] 4) Secondary mixing: Use a turning machine and grab bucket to thoroughly mix the material in the thick layer until there are no obvious agglomerates or lumps;

[0037] 5) Sintering: A base material and a raw material layer are laid from bottom to top in the sintering machine. Then, the mixture after secondary mixing is fed into the sintering machine and laid on the raw material layer using a belt. Finally, another raw material layer is laid on the mixture after secondary mixing to form a sintering material layer. The sintering material layer is preheated, sintered and cooled in sequence.

[0038] 6) Crushing and screening to obtain sintered ore.

[0039] Among them, oily sludge is a difficult-to-dispose-of solid waste containing iron scale, lubricating oil, water, etc., generated from processes such as cold rolling, hot rolling, continuous casting, and steel pipe production in steel plants; desulfurization slag is a desulfurization byproduct of calcium-based fixed-bed desulfurization processes; converter steel slag tailings are steel slag tailings with a particle size of 0-3mm after magnetic separation and screening; and sintered return ore is incompletely sintered ore with a particle size ≤5mm after sieving. Figure 1 As shown, the sintering material layer inside the sintering machine consists of four layers from bottom to top: the base material, the raw material layer, the mixed material after secondary mixing, and the raw material layer.

[0040] Example 2:

[0041] A method for the co-processing and utilization of metallurgical solid and hazardous waste, wherein the raw materials are proportioned by weight as follows: 3 parts oily sludge, 10 parts desulfurization slag, 15 parts converter steel slag, and 72 parts sintered return ore, and includes the following steps:

[0042] 1) Primary mixing: The oily sludge, desulfurization slag and converter steel slag tailings are mixed evenly in a ratio of 3:10:15 in a high-power mixer to complete the first dispersion treatment of the oily sludge.

[0043] 2) Spreading: Spread the mixed material after one mixing with the sintered return ore at a weight ratio of 28:72 on the ground of the hazardous waste storage room, with the sintered return ore being 30-40cm thick; spread the mixed material after one mixing on top of the sintered return ore, with the mixed material being 3-5cm thick.

[0044] 3) Repeat the above two steps once, and then lay another layer of sintered return ore and another layer of the mixture after the first mixing on the top of the mixture, so as to form a thick layer of 66-90cm. Let it stand for 2 hours.

[0045] 4) Secondary mixing: Use a turning machine and grab bucket to thoroughly mix the material in the thick layer until there are no obvious agglomerates or lumps;

[0046] 5) Sintering: A base material and a raw material layer are laid from bottom to top in the sintering machine. Then, the mixture after secondary mixing is fed into the sintering machine and laid on the raw material layer using a belt. Finally, another raw material layer is laid on the mixture after secondary mixing to form a sintering material layer. The sintering material layer is preheated, sintered and cooled in sequence.

[0047] 6) Crushing and screening to obtain sintered ore.

[0048] Among them, oily sludge is a difficult-to-dispose-of solid waste containing iron scale, lubricating oil, water, etc., generated from processes such as cold rolling, hot rolling, continuous casting, and steel pipe production in steel plants; desulfurization slag is a desulfurization byproduct of calcium-based fixed-bed desulfurization processes; converter steel slag tailings are steel slag tailings with a particle size of 0-3mm after magnetic separation and screening; and sintered return ore is incompletely sintered ore with a particle size ≤5mm after sieving. Figure 1 As shown, the sintering material layer inside the sintering machine consists of four layers from bottom to top: the base material, the raw material layer, the mixed material after secondary mixing, and the raw material layer.

[0049] Example 3:

[0050] A method for the co-processing and utilization of metallurgical solid and hazardous waste, wherein the raw materials are proportioned by weight as follows: 3 parts oily sludge, 20 parts desulfurization slag, 10 parts converter steel slag, and 67 parts sintered return ore, and includes the following steps:

[0051] 1) Primary mixing: The oily sludge, desulfurization slag and converter steel slag tailings are mixed evenly in a high-power mixer at a ratio of 3:20:10 to complete the first dispersion treatment of the oily sludge.

[0052] 2) Spreading: Spread the mixed material after one mixing with the sintered return ore at a weight ratio of 33:67 on the ground of the hazardous waste storage room. The sintered return ore should be 30-40cm thick. Spread the mixed material after one mixing on top of the sintered return ore. The mixed material should be 3-5cm thick.

[0053] 3) Repeat the above two steps once, and then lay another layer of sintered return ore and another layer of the mixture after the first mixing on the top of the mixture, so as to form a thick layer of 66-90cm. Let it stand for 2 hours.

[0054] 4) Secondary mixing: Use a turning machine and grab bucket to thoroughly mix the material in the thick layer until there are no obvious agglomerates or lumps;

[0055] 5) Sintering: A base material and a raw material layer are laid from bottom to top in the sintering machine. Then, the mixture after secondary mixing is fed into the sintering machine and laid on the raw material layer using a belt. Finally, another raw material layer is laid on the mixture after secondary mixing to form a sintering material layer. The sintering material layer is preheated, sintered and cooled in sequence.

[0056] 6) Crushing and screening to obtain sintered ore.

[0057] Among them, oily sludge is a difficult-to-dispose-of solid waste containing iron scale, lubricating oil, water, etc., generated from processes such as cold rolling, hot rolling, continuous casting, and steel pipe production in steel plants; desulfurization slag is a desulfurization byproduct of calcium-based fixed-bed desulfurization processes; converter steel slag tailings are steel slag tailings with a particle size of 0-3mm after magnetic separation and screening; and sintered return ore is incompletely sintered ore with a particle size ≤5mm after sieving. Figure 1 As shown, the sintering material layer inside the sintering machine consists of four layers from bottom to top: a base layer, a raw material layer, a mixture after secondary mixing, and another raw material layer. Any other parts not described are existing technologies.

Claims

1. A method for the co-processing and utilization of metallurgical solid and hazardous waste, characterized in that: Using oily sludge, desulfurization slag, converter steel slag tailings, and sintered return ore as raw materials, the process includes the following steps: 1) Primary mixing: The oily sludge, desulfurization slag and converter steel slag tailings are put into a high-power mixer in a set ratio and mixed evenly to complete the first dispersion treatment of the oily sludge. 2) Spreading: Spread the sintered return ore on the ground of the hazardous waste storage room; spread the mixture after one mixing on the top layer of sintered return ore; the weight ratio of the mixture after one mixing to the sintered return ore is 21-28:67-79; the spreading thickness of the sintered return ore is 30-40cm; the spreading thickness of the mixture after one mixing is 3-5cm. 3) Repeat the mixing and spreading process once: alternately spread the sintered return ore and the mixture after the first mixing to form a thick material layer, and let it stand for 1-2 hours; 4) Secondary mixing: The material in the thick layer is mixed a second time until there are no obvious agglomerates or lumps; 5) Sintering: A base material and a raw material layer are laid from bottom to top in the sintering machine beforehand. Then, the mixture after secondary mixing is sent to the sintering machine and laid on the raw material layer. Finally, another raw material layer is laid on the mixture after secondary mixing to form a sintering material layer. The sintering material layer is preheated, sintered and cooled in sequence. 6) Crushing and screening to obtain sintered ore; The mass proportions of the raw materials are as follows: 1-3 parts oily sludge, 10-20 parts desulfurization slag, 10-15 parts converter steel slag tailings, and 67-79 parts sintering return ore.

2. The method for co-processing and utilizing metallurgical solid and hazardous waste according to claim 1, characterized in that: The oily sludge is a difficult-to-dispose solid waste produced by steel plants, containing iron scale, lubricating oil, and water.

3. The method for co-processing and utilizing metallurgical solid and hazardous waste according to claim 1, characterized in that: The desulfurization residue is a desulfurization byproduct of the calcium-based fixed-bed desulfurization process.

4. The method for co-processing and utilizing metallurgical solid and hazardous waste according to claim 1, characterized in that: The converter slag tailings are steel slag tailings with a particle size of 0-3mm after magnetic separation and screening.

5. The method for co-processing and utilizing metallurgical solid and hazardous waste according to claim 1, characterized in that: The sintered return ore refers to incompletely sintered ore with a particle size ≤5mm after sieving.

6. The method for co-processing and utilizing metallurgical solid and hazardous waste according to claim 1, characterized in that: In step 3), the thickness of the thick material layer is 66-90cm.

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